Controllers that accommodate an electronic circuit board and the like in a metallic case have been typically known in various fields (see, for instance, Patent Literature 1). A case used for such a controller is grounded to a frame ground for the purpose of, for instance, electromagnetic shielding of the interior electronic circuit board.
When being installed on a construction machine, the controller is attached to an attachment board on a vehicle body via an attachment provided on the case. A cable harness to be connected to the controller includes a ground cable for frame ground. The ground cable is drawn out of an end of the controller separately from the other cables. While the other cables are electrically connected to the electronic circuit board inside the controller via a connector, the ground cable is fastened to the attachment board through a terminal attached to an end thereof together with a mount of the case, so that the case is electrically conducted with the ground cable and is grounded to the frame ground.